From west to east, the Ruhr includes the cities of Duisburg,
Oberhausen, Bottrop, Mülheim an der Ruhr, Essen, Gelsenkirchen,
Bochum, Herne, Hagen, Dortmund, and Hamm, as well as parts of the more
"rural" districts of Wesel, Recklinghausen, Unna and
Ennepe-Ruhr-Kreis. Historically, the western Ruhr towns, such as
Duisburg and Essen, belonged to the historic region of the Rhineland,
whereas the eastern part of the Ruhr, including Gelsenkirchen, Bochum,
Dortmund and Hamm, were part of the region of Westphalia. Since the
19th century, these districts have grown together into a large complex
with a vast industrial landscape, inhabited by some 7.3 million people
(including Düsseldorf and Wuppertal).
It is the fifth largest urban area in Europe after Istanbul, Moscow, London and Paris...
..taken at the Ruhr Museum in Zollverein...